scholarly journals Heteroaryl-Ethylenes as New Lead Compounds in the Fight against High Priority Bacterial Strains

2021 ◽  
Author(s):  
Dafne Bongiorno ◽  
Nicolò Musso ◽  
Paolo Giuseppe Bonacci ◽  
Dalida A. Bivona ◽  
Mariacristina Massimino ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Rectal Adenocarcinoma ◽  
Molecular Structures ◽  
Bacteriostatic Activity ◽  
Bacterial Strains ◽  
Biological Assays ◽  
Antibiotic Compounds ◽  
Stilbene Derivatives ◽  
New Type ◽  
Activity Spectrum

The widespread use of antibiotics has led to a gradual increase in drug-resistant bacterial infections, which severely weakens the clinical efficacy of antibacterial therapies. In recent decades, stilbenes aroused great interest because of their high bioavailability, as well as for their manifold biological activity. Our research efforts are focused on synthetic heteroaromatic stilbene deriva-tives as they represent a potentially new type of antibiotic with a wide antibacterial spectrum. Herein, a preliminary molecular modeling study and a versatile synthetic scheme allowed us to define eight heteroaromatic stilbene derivatives with potential antimicrobial activity. In order to evaluate our compound’s activity spectrum and antibacterial ability, Minimum Inhibitory Con-centration (MIC) and Minimum Bactericidal Concentration (MBC) tests have been performed on Gram-positive and Gram-negative ATCC strains. Compounds PB4, PB5, PB7 and PB8 showed the best values in terms of MIC and were also evaluated for MBC, which however was found to be greater than MIC, confirming a bacteriostatic activity. For all compounds, we evaluated toxici-ty on colon-rectal adenocarcinoma cells tumor cells (CaCo2), once established that the whole se-lected set was more active than 5-Fluorouracil in reducing CaCo-2 cells viability. To the best of our knowledge, the biological assays have shown for these derivatives an excellent bacteriostatic activity, compared to similar molecular structures previously reported, thus paving the way for a new class of antibiotic compounds.

scholarly journals Heteroaryl-Ethylenes as New Lead Compounds in the Fight against High Priority Bacterial Strains

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1034
Author(s):  
Dafne Bongiorno ◽  
Nicolò Musso ◽  
Paolo G. Bonacci ◽  
Dalida A. Bivona ◽  
Mariacristina Massimino ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Rectal Adenocarcinoma ◽  
Molecular Structures ◽  
Bacteriostatic Activity ◽  
Bacterial Strains ◽  
Biological Assays ◽  
Antibiotic Compounds ◽  
Stilbene Derivatives ◽  
New Type ◽  
Activity Spectrum

The widespread use of antibiotics has led to a gradual increase in drug-resistant bacterial infections, which severely weakens the clinical efficacy of antibacterial therapies. In recent decades, stilbenes aroused great interest because of their high bioavailability, as well as their manifold biological activity. Our research efforts are focused on synthetic heteroaromatic stilbene derivatives as they represent a potentially new type of antibiotic with a wide antibacterial spectrum. Herein, a preliminary molecular modeling study and a versatile synthetic scheme allowed us to define eight heteroaromatic stilbene derivatives with potential antimicrobial activity. In order to evaluate our compound’s activity spectrum and antibacterial ability, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests have been performed on Gram-positive and Gram-negative ATCC strains. Compounds PB4, PB5, PB7, and PB8 showed the best values in terms of MIC and were also evaluated for MBC, which was found to be greater than MIC, confirming a bacteriostatic activity. For all compounds, we evaluated toxicity on colon-rectal adenocarcinoma cells tumor cells (CaCo2), once it was established that the whole selected set was more active than 5-Fluorouracil in reducing CaCo-2 cells viability. To the best of our knowledge, the biological assays have shown for these derivatives an excellent bacteriostatic activity, compared to similar molecular structures previously reported, thus paving the way for a new class of antibiotic compounds.

STUDIES ON SOME BACTERIAL DISEASES IN OREOCHROMIS NILOTICUS WITH SPECIAL REFERENCES TO TREATMENT

2018 ◽  
pp. 39-47
Author(s):  
Viola Zaki ◽  
Ahmed EL-gamal ◽  
Yasmin Reyad
Keyword(s):  
Oreochromis Niloticus ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Histopathological Examination ◽  
Klebsiella Oxytoca ◽  
Bacterial Isolates ◽  
Bacterial Strains ◽  
Tissue Samples ◽  
Hydropic Degeneration ◽  
Total Prevalence

he present research carried out to study the common bacterial infections in Oreochromis niloticus (Nile tilapia) in Manzala area at Dakahlia governorate and possible antimicrobial agents used for treatment. A total number of 400 fish were randomly collected from Manzala private farms at Dakahlia governorate and subjected to the clinical, bacteriological and histopathological examination. The highest prevalence of bacterial isolates during the whole period of examination of naturally infected O.niloticus was recorded for A.hydrophila (22.66%), followed by V.alginolyticus (19.01%), V.parahemolyticus (13.80%), Streptococcus spp. (12.24%), A.caviae (11.72%), V.cholera (10.16%), A.salmonicida (7.55%), while the lowest prevalence was recorded for Klebsiella oxytoca (2.86%). The seasonal highest total prevalence of bacterial isolates from examined naturally infected O. niloticus was recorded in spring (30.21%), followed by autumn (28.39%), then summer (22.40%) and the lowest prevalence was recorded in winter (19.01%). Histopathological findings of the tissue samples which collected from different organs of naturally infected O.niloticus revealed that spleen show marked hemosiderosis and sever hemorrhage, gills showsever congestion of lamellar capillaries with marked aneurysm, necrosis and hemorrhage of lamellar epithelium and liver show sever hydropic degeneration and necrosis of hepatocytes, Ciprofloxacin was the most effective antibiotic against all isolated bacterial strains

Repurposing of auranofin against bacterial infections: An In silico and In vitro study

2020 ◽  
Vol 16 ◽  
Author(s):  
Nidhi Sharma ◽  
Arti Singh ◽  
Ruchika Sharma ◽  
Anoop Kumar
Keyword(s):  
Broad Spectrum ◽  
In Silico ◽  
Antibacterial Agent ◽  
Bacterial Infections ◽  
In Vitro Assays ◽  
Infection Model ◽  
Synergistic Activity ◽  
Bacterial Strains ◽  
Molecular Docking Study

Aim: The aim of the study was to find out the role of auranofin as a promising broad spectrum antibacterial agent. Methods: In-vitro assays (Percentage growth retardation, Bacterial growth kinetics, Biofilm formation assay) and In-silico study (Molegro virtual docker (MVD) version 6.0 and Molecular operating environment (MOE) version 2008.10 software). Results: The in vitro assays have shown that auranofin has good antibacterial activity against Gram positive and Gram negative bacterial strains. Further, auranofin has shown synergistic activity in combination with ampicillin against S. aureus and B. subtilis whereas in combination with neomycin has just shown additive effect against E. coli, P. aeruginosa and B. pumilus. In vivo results have revealed that auranofin alone and in combination with standard drugs significantly decreased the bioburden in zebrafish infection model as compared to control. The molecular docking study have shown good interaction of auranofin with penicillin binding protein (2Y2M), topoisomerase (3TTZ), UDP-3-O-[3- hydroxymyristoyl] N-acetylglucosaminedeacetylase (3UHM), cell adhesion protein (4QRK), β-lactamase (5CTN) and arylsulphatase (1HDH) enzyme as that of reference ligand which indicate multimodal mechanism of action of auranofin. Finally, MTT assay has shown non-cytotoxic effect of auranofin. Conclusion: In conclusion, auranofin in combination with existing antibiotics could be developed as a broad spectrum antibacterial agent; however, further studies are required to confirm its safety and efficacy. This study provides possibility of use of auranofin apart from its established therapeutic indication in combination with existing antibiotics to tackle the problem of resistance.

scholarly journals Silver (I) N-Heterocyclic Carbene Complexes: A Winning and Broad Spectrum of Antimicrobial Properties

2021 ◽  
Vol 22 (5) ◽  
pp. 2497
Author(s):  
Filippo Prencipe ◽  
Anna Zanfardino ◽  
Michela Di Napoli ◽  
Filomena Rossi ◽  
Stefano D’Errico ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Antimicrobial Properties ◽  
Resistance Mechanisms ◽  
Heterocyclic Carbenes ◽  
Significant Activity ◽  
Bacterial Strains ◽  
Development Of Resistance ◽  
Starting Point ◽  
Catalytic Chemistry

The evolution of antibacterial resistance has arisen as the main downside in fighting bacterial infections pushing researchers to develop novel, more potent and multimodal alternative drugs.Silver and its complexes have long been used as antimicrobial agents in medicine due to the lack of silver resistance and the effectiveness at low concentration as well as to their low toxicities compared to the most commonly used antibiotics. N-Heterocyclic Carbenes (NHCs) have been extensively employed to coordinate transition metals mainly for catalytic chemistry. However, more recently, NHC ligands have been applied as carrier molecules for metals in anticancer applications. In the present study we selected from literature two NHC-carbene based on acridinescaffoldand detailed nonclassicalpyrazole derived mono NHC-Ag neutral and bis NHC-Ag cationic complexes. Their inhibitor effect on bacterial strains Gram-negative and positivewas evaluated. Imidazolium NHC silver complex containing the acridine chromophore showed effectiveness at extremely low MIC values. Although pyrazole NHC silver complexes are less active than the acridine NHC-silver, they represent the first example of this class of compounds with antimicrobial properties. Moreover all complexesare not toxic and they show not significant activity againstmammalian cells (Hek lines) after 4 and 24 h. Based on our experimental evidence, we are confident that this promising class of complexes could represent a valuable starting point for developing candidates for the treatment of bacterial infections, delivering great effectiveness and avoiding the development of resistance mechanisms.

scholarly journals Prevalence and Detection of qac Genes from Disinfectant-Resistant Staphylococcus aureus Isolated from Salon Tools in Ishaka Town, Bushenyi District of Uganda

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Solange Gahongayire ◽  
Adamu Almustapha Aliero ◽  
Charles Drago Kato ◽  
Alice Namatovu
Keyword(s):  
Sodium Hypochlorite ◽  
Quaternary Ammonium ◽  
Bacterial Infections ◽  
Healthcare Providers ◽  
Quaternary Ammonium Compound ◽  
Diffusion Method ◽  
Ammonium Compound ◽  
Bacterial Strains ◽  
Microbiological Methods ◽  
Phenotypic Methods

Bacterial infections are on a rise with causal-resistant strains increasing the economic burden to both patients and healthcare providers. Salons are recently reported as one of the sources for transmission of such resistant bacterial strains. The current study aimed at the identification of the prevalent bacteria and characterization of quaternary ammonium compound (qac) genes from disinfectant-resistant S. aureus isolated from salon tools in Ishaka town, Bushenyi District of Uganda. A total of 125 swabs were collected from different salon tools (combs, brushes, scissors, clippers, and shaving machines), and prevalent bacteria were isolated using standard microbiological methods. Identification of isolated bacteria was done using standard phenotypic methods including analytical profile index (API). Susceptibility patterns of the isolated bacteria to disinfectant were determined using the agar well diffusion method. Quaternary ammonium compound (qac) genes (qacA/B and qacC) associated with disinfectant resistances were detected from disinfectant-resistant S. aureus using multiplex polymerase chain reaction (PCR) and Sanger sequencing methods. Of the 125 swab samples collected from salons, 78 (62.4%) were contaminated with different bacteria species. Among the salon tools, clippers had the highest contamination of 20 (80.0%), while shaving machines had the lowest contamination of 11 (44.0%). The most prevalent bacteria identified were Staphylococcus epidermidis (28.1%) followed by S. aureus (26.5%). Of all the disinfectants tested, the highest resistance was shown with sodium hypochlorite 1%. Out of the eight (8) disinfectant-resistant S. aureus analysed for qac genes, 2 (25%) isolates (STP6 and STP9) were found to be qacA/B positive, while 2 (25%) isolates (STP8 and STP9) were found to be qacC gene positive. This study has shown that bacterial contamination of salon tools is common, coupled with resistance to disinfectants with sodium hypochlorite resistance being more common. Furthermore, observed resistance was attributed to the presence of qac genes among S. aureus isolates. A search for qac genes for disinfectant resistance from other bacteria species is recommended.

scholarly journals Evaluation of Lipases from Wild Microbial Strains as Biocatalysts in Biodiesel Production

Separations ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 53 ◽  
Author(s):  
Carlos Luna ◽  
Diego Luna ◽  
Felipa Bautista ◽  
Juan Calero ◽  
Antonio Romero ◽  
...  
Keyword(s):  
Biodiesel Production ◽  
Purification Process ◽  
Bacterial Strains ◽  
Production Methods ◽  
Mild Conditions ◽  
New Type ◽  
Microbial Strains ◽  
The Stability ◽  
Microbial Strain ◽  
Biodiesel Industry

In this study, the evaluation of the catalytic behavior of several wild bacterial strains in the 1,3-selective ethanolysis of triglycerides with ethanol to produce a new type of biodiesel (Ecodiesel) that integrates glycerol as monoacylglycerols was carried out. The Ecodiesel production not only avoids the elimination of glycerol, which is largely generated as a by-product in the biodiesel industry, but also results in an increase in the biofuel yield. The wild microbial strain samples were obtained from several lipophilic organisms. In addition to evaluate the enzymatic extracts, the minimum grade of purification of the strains, necessary to obtain similar results to those attained with commercial lipases was studied. This purification treatment included a dialysis followed by a lyophilization process. Such extracts were directly used as biocatalysts in the transesterification reaction of sunflower oil with ethanol, attaining much better results (yield close to 100%) than those obtained with strains which were not submitted to the purification process (yields lower than 10%). Furthermore, the results here obtained are similar to those obtained with commercial lipases but were achieved under mild conditions and lower reaction time (2 h). In addition, the stability of the enzymatic extracts was corroborated by subsequent reactions, showing no loss of activity. Thus, this study brings to light that enzymatic extracts obtained by a very simple purification process can be economically competitive with the conventional biodiesel production methods.

scholarly journals Imaging Sensitive and Drug-Resistant Bacterial Infection with [11C]-TMP: In Vitro and First-in-Human Evaluation

2021 ◽  
Author(s):  
Iris K Lee ◽  
Daniel A Jacome ◽  
Joshua K Cho ◽  
Vincent Tu ◽  
Anthony Young ◽  
...  
Keyword(s):  
Bacterial Infection ◽  
Mammalian Cells ◽  
Bacterial Infections ◽  
The Body ◽  
Response Monitoring ◽  
Drug Resistant ◽  
Bacterial Strains ◽  
Critical Question ◽  
In Vitro Uptake

Recently, several molecular imaging strategies have developed to image bacterial infections in humans. Nuclear approaches, specifically positron emission tomography (PET), affords sensitive detection and the ability to non-invasively locate infections deep within the body. Two key radiotracer classes have arisen: metabolic approaches targeting bacterial specific biochemical transformations, and antibiotic-based approaches that have inherent selectivity for bacteria over mammalian cells. A critical question for clinical application of antibiotic radiotracers is whether resistance to the template antibiotic abrogates specific uptake, thus diminishing the predictive value of the diagnostic test. We recently developed small-molecule PET radiotracers based on the antibiotic trimethoprim (TMP), including [11C]-TMP, and have shown their selectivity for imaging bacteria in preclinical models. Here, we measure the in vitro uptake of [11C]-TMP in pathogenic susceptible and drug-resistant bacterial strains. Both resistant and susceptible bacteria showed similar in vitro uptake, which led us to perform whole genome sequencing of these isolates to identify the mechanisms of TMP resistance that permit retained radiotracer binding. By interrogating these isolate genomes and a broad panel of previously sequenced strains, we reveal mechanisms where uptake or binding of TMP radiotracers can potentially be maintained despite the annotation of genes conferring antimicrobial resistance. Finally, we present several examples of patients with both TMP-sensitive and drug-resistant infections in our first-in-human experience with [11C]-TMP. This work underscores the ability of an antibiotic radiotracer to image bacterial infection in patients, which may allow insights into human bacterial pathogenesis, infection diagnosis, and antimicrobial response monitoring.

scholarly journals Investigation of the antimicrobial activity of danofoloxacin against bacteria pathogens in goats

2020 ◽  
Vol 22 (97) ◽  
pp. 74-78
Author(s):  
T. I. Stetsko ◽  
Ya. M. Liubenko ◽  
V. N. Padovskyi ◽  
L. L. Ostrovska ◽  
O. Yo. Kalinina ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Bacterial Infections ◽  
Chemotherapeutic Agents ◽  
Diffusion Method ◽  
Bacteriostatic Activity ◽  
Intestinal Infection ◽  
Sensitivity Testing ◽  
First Choice

Fluoroquinolones are critical antimicrobials for both human and veterinary medicine. Due to their unique mechanism of antimicrobial action and good pharmacokinetic properties, they are often the first choice drugs in the treatment of bacterial infections in animals. The purpose of the investigation was to study the antimicrobial activity of a third-generation fluoroquinolone antibiotic of danofloxacin against bacteria, pathogens of respiratory and intestinal infection in goats. The samples of the nasal outflows (respiratory infection) and fecal masses (intestinal infection) were collected from clinically ill goats for microbiological studies. The sensitivity test of the microflora of the biomaterial, carried out by the disco-diffusion method, showed that the microorganisms of all the samples were sensitive to danofloxacin. Bacteria Streptococcus pneumonia (n = 10), Staphylococcus aureus (n = 4) and Escherichia coli (n = 2) were isolated and identified from nasal exudate samples (n = 10). Pathogenic strains of Escherichia coli were isolated from all faecal samples (n = 12). The degree of bacteriostatic activity of danofloxacin was determined by establishing its minimum inhibitory concentration (MIC) for bacterial isolates by sequential dilutions in a liquid nutrient medium. The average MIC of danofloxacin for Streptococcus pneumoniae isolates was 0.26 ± 0.13 μg/ml and for Staphylococcus aureus isolates – 0.25 ± 0.075 μg/ml. For Escherichia coli strains isolated from faeces of goats suffering from coli infection, the average MIC of danofloxacin was 0.38 ± 0.12 μg/ml (range 0.2 to 0.8 μg/ml). Antimicrobial sensitivity testing have shown a high level of bacteriostatic activity of danofloxacin against bacteria, pathogens of respiratory and intestinal infections in goats. This may be the argument for the use of danofloxacin-based chemotherapeutic agents in the treatment of bacterial infections in goats, especially for the empirical approach to therapy.

Synthesis of C-aryl-N-(2-hydroxyphenylmethyl)-nitrones and their reaction with diphenylborinic or carboxylic acid derivatives. Crystal and molecular structures of a free nitrone ligand and its diphenyl–boron chelate

1997 ◽  
Vol 75 (12) ◽  
pp. 1830-1843 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Jörg Metge ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Carboxylic Acid ◽  
Electron Distribution ◽  
Direct Methods ◽  
Molecular Structures ◽  
State Structure ◽  
Space Group ◽  
Crystal And Molecular Structures ◽  
New Type ◽  
Boron Chelate ◽  
Diphenylboron Chelate

The syntheses of a number of aromatic aldonitrones of N-(2-hydroxyphenylmethyl)hydroxylamine and their subsequent reactions with diphenylborinic or carboxylic acid derivatives are reported. Crystals of 8-(4-dimethylaminophenylmethylene)-6,6-diphenyl-5,7-dioxa-8-azonia-6-borata-5H-6,7,8,9-tetrahydrobenzocycloheptene, 2b, are triclinic, a = 10.6802(8), b = 11.1809(4), c =10.1520(3) Å, α = 105.847(3)°, β = 92.567(4)°, γ = 84.610(5)°, Z = 2, space group PĪ, and those of C-(4-dimethylaminophenyl)-N-(2-hydroxyphenylmethyl)nitrone, 6e, are monoclinic, a = 12.2319(8), b = 7.071(1), c = 17.2005(9) Å, β = 107.520(4)°, Z = 4, space group P21/a. The structures were solved by direct methods and refined by full-matrix least-squares procedures to R = 0.035 and 0.032 (Rw = 0.036 and 0.032) for 3379 and 1800 reflections with I ≥ 3σ(I), respectively. Compound 2b is representative of a new type of heterocyclic B,N-betaine. The solid state structure of 6e (the precursor to 2b) shows that only small topological changes, but significant changes in the electron distribution, occur upon the formation of the diphenylboron chelate. Keywords: aromatic aldonitrones, organoboron compounds, crystal structures.

scholarly journals Regioselective Synthesis of Novel [N-(4-Oxo-3-(2-phenyl-1,8-naphthyridin-3-yl)-thiazolidin-2-ylidene)]acetamide/benzamides and their Biological Activity

2019 ◽  
Vol 31 (6) ◽  
pp. 1246-1250
Author(s):  
RAMALINGAM KUNDENAPALLY ◽  
RAMESH DOMALA ◽  
B. SREENIVASULU
Keyword(s):  
Biological Activity ◽  
Bacterial Infections ◽  
Antibacterial Agents ◽  
Regioselective Synthesis ◽  
Chloroacetyl Chloride ◽  
Bacterial Strains ◽  
Physical Data

In an attempt to discover the new antibacterial agents to fight the bacterial infections, a series of 1,8-naphthyridine based 2-iminothiazolidin-4-one derivatives was synthesized by a straight-forward regioselective synthesis. 2-Phenyl-1,8-naphthyridin-3-amine (2) was reacted with acetyl or aroyl isothiocyantes to give the corresponding N-[(2-phenyl-1,8-naphthyridin-3-yl)carbamothioyl)]acetamide or benzamides (3a-e). Finally, the target compounds [N-(4-oxo-3-(2-phenyl-1,8-naphthyridin-3-yl)thiazolidin-2-ylidene)]acetamide or benzamides (4a-e) were obtained by the reaction of thiourea (3a-e) with chloroacetyl chloride in presence of pyridine. All the synthesized products were formed in good yields and their structures were characterized by spectral (IR, EI-MS and NMR) and physical data. The biological activity of title compounds was evaluated against the bacterial strains and found to be more potent.

Sign in / Sign up

Export Citation Format

Share Document